Method of protectively coating containers



June 18, 1929. c, T, DRAPER 1,718,039

METHOD OF PROTECTIVELY COATING CONTAINERS Filed Feb. 5, 1925 2 Sheets-Sheet l TTOENEY June 18, 1929. c, DRAPER, 1,718,039

METHOD OF PROTECTIVELY COATING CONTAINERS Filed Feb. 5, 1925 2 Sheets-Sheet 2 Patented June 18, 1929.

' UNITED STATES 1,718,039 PATENT OFFICE.

crumbles T. 15mm, or cnnvnmn, OHIO, assrenon .To THE nmrnn mmnmc- TUBING columnar, OF CLEVELAND, 01110, A CORPORATION or 01110.

METHOD or rnoTEcTivEnY conTme CONTAINERS.

Application filed February 5, 1925. Serial No. 7,015.

My invention relates toimprovements in method of protectively coating sheet metal containers, and has for its object a proce distribution of the coating material throu hout the interior of a container and it requently is the common practice tomake du-' plicate or triple applications of the material in order measurably to insure a complete covering of the surfaces. Frequently, as with barrels and drums formed of sheet metal, this coverage merely is assumed, since the operative cannot visually assure himself of any complete application of the protective coating, while uneven distribution and unnecessary expense almost certainly are invglved through practicing the prior metho s.

Accordingly, I have devised an improved method for protectively coating various classes of sheet metal containers by introducing a quantity of suitable coating sub-' stance that is rendered fluid upon heating the container; meanwhile rotating t-he'heated container to insure distribution of the liquefied substance evenly over its interior surfaces. In order to insure the even and economical coverage of all interior surfaces and seams, it is found desirable to apply the coating material to the blanks from which the container is fabricated before they are seamed together; all as will be more fully explained in the accompanying specification and claims, having particular reference to the drawings, wherein:

Figure 1 is a perspective view of the ey lindrical shell for fornfing a sheet metal drum,

Fig. 2 is a similar view of a head therefor, Fig-L3 is a fragmentary sectional view upon an enlarged scale illustrating the evenly applied interior coating,

Fig. 4 is a diagrammatic plan view of apparatus adapted for practicing my improved method,

Fig. -5 is -a longitudinal sectional view thereof on line V-V, Fig. 4, i

Fig. 6 is an enlarged cross sectional view.

suitable protective material or substancewhich becomes'liquid or ,vaporous with the application of moderateheat and which can readily be dried orsolidified by cooling is one lending itself to the instant method. Nevertheless, I may'suiliciently explain my invention by describing the application of a paraffin'coating, preferably distributed over areas of the blanks prior to seaming them and testing the completed drum. I

"The sheet metal drum 0:, shown in completed form in Figs. 3, 6 and 7, may be taken as typical of any sheet metal container; comprising in this instance the cylindrical shell a. and the heads'a" that are seamed together in the well known manner to produce a liquid-tight container. These members or blanks may have adequate quantities of coating material applied thereto in distributed areas, as c, a, respectively applied to the body portion and to the heads as shown. We may assume that the desired I coating is paraffin, which may be applied in liquid form promptly solidifying in irregular form when brought in contact with the metal. The drum thereupon is suitably seamed circumferentially of the heads, as as shown in'Fig. 6,'whereupon it may be subjected to the usual tests before the coating is distributed.

On the other hand, it may be found desirable to introduce the coating substance after the completion and testing of the sheet metal container, which may be done through the opening I) provided with the usual screwclosure member 6'. The coating substance may be sprayed through said openmg, or it may be melted and poured 1n tp the container according to its characteristics and fully 1n accordance with the spirit and intent of my present invention. It may be observed here that when substances volatilizing at relatively low temperatures are employed for the coating material, it is necessary to insert the closure member I) in the opening, and frequently this is desirable during the heating period, in any case, in order to safeguard the coating material and prevent the entrance of foreign substances.

In my application, Ser. No. 728,535, July 28th, 1924,.1 have shown apparatus, partly reproduced in the accompanying drawings,

, adapted for practicing my present improvement, although I wish it to be understood that the same is quite independent of the means for accomplishing the procedure and method hereinafter claimed.

Referring then to the second sheet of I drawings, an elongated tunnel at is diagrammatically shown in Fig. 4 equipped with heaters e, e adapted to direct currents of heated air in both directions intermediately of said tunnel. A loadin station and 'platform 7 appear upon the rig t, while the coated containers a, a are removed from the conveyor g after passing beyond the tunnel and after being cooled. The details of the traveling conveyor 9 may be explained by referring to Figs. 6 and 7 wherein the supporting rails in are engaged by the chime of the container, while rollers '13, provided upon the upper pass of the linked conveyor j,serve slowly to advance the containers by rolling them alongthe rails from one end of the heated tunnel to the other. L-shaped rails it serve to support the lower or returning section of the linked conveyor; therespective movements thereof and of the rotated containers being indicated by darts, Fig. 7.

Quite obviouslythe degree of heat to which the containers shall be subjected is governed primarily by the character of the coating material; paraffin, herein assumed for the purpose of illustration, melting and flowing freely approximately at 150 F. Accordingly, the liquid coating material, as

paraffin, will readily flow byer the surfaces of the heads and interiorly, of the body of the container as it is rolled through the heated tunnel, thereby evenly distributing the coating material over the surfaces of the metal, where it will remain upon permitting the container to cool exteriorly of the tunnel and during rotation thereof. Thus the con talners may very expeditiously and cheaply be provided with an interior protective coating that is certain to cover all of the surfaces and scams interiorly thereof, sim' ly by availing of the expedient of rolling't e conapparatus disclosed, nor. to the tainers, which consists in applying a quantity of a substance that is solid at normal temperatures and fluid at higher temper'a-' tures to the inner surface of the blank, comi I pleting the sheet metal container, heating said container and the contained substance sufliciently to render the latter fluid, rotating said container, and permitting it to cool after the substance has been evenly distributed over the interior surfaces of the container substantially as set forth.

2. The herein described method of applying an interior protective coating to sheet metal barrels and drums, which consists in placing suflicient quantities of a substance that is solid at normal temperatures and fluid at higher temperatures upon the inner surfaces of the heads and body blank, seaming and testing the sheet metal container, heating said container sufiiciently to render the coating substance fluid, rotating the container in heated condition, and permitting it to cool after the .coa'tinghas been evenly distributed over the interior surfaces of the container, substantially as set forth.

3. The herein describedmethod of applying an interior protective coating to sheet metal barrels and drums, which consists indistributing approximately the required quantities of a substance that is solid at normal temperatures and fluid at higher temperatures upon the inner surfaces of the heads and shell in adjacent covering positions, seaming the sheet metal con tainer, heating said container sufliciently to render the coating substance fluid, rotating the container in heated condition and permitting it to cool initially while rotating after the'coating has been evenly distributed over the interior surfaces of the container, substantially as set forth.

In testimony whereof I ,do now afiix my signature.

CHARLE$ DRAPER. 

